2. A bag contains 6 Red, 5 Green and 4 Yellow coloured balls. 2 balls are drawn at random after one another without replacement then what is the probability that atleast one ball is Green.
(a).
(b).
(c).
(d).
(e).

Probability Questions for IBPS RRB 2013 Exam

1. If 4 marbles are drawn at random, what is the probability that 2 are red and 2 are blue ?
(a).
(b).
(c).
(d).
(e). None of these

2. If 2 marbles are drawn at random, what is the probability that both are green ?
(a).
(b).
(c).
(d).
(e). None of these

3. If 3 marbles are drawn at random. What is the probability that none is red ?
(a).
(b).
(c).
(d).
(e). None of these

From the following, different committees are to be made as per the requirement given in each question.
In how many different ways can it be done ? (IBPS RRB OS 2013)
10 men and 8 women out of which 5 men are teachers, 3 men doctors and businessmen. Among the women, 3 are teachers, 2 doctors, 2 researchers and 1 social worker.

4. A Committee of 5 in which 3 men and 2 women are there
(a). 3360
(b). 8568
(c). 4284
(d). 1680
(e). None of these

5. A Committee of 4 in which at least 2 women are there
(a). 1260
(b). 1820
(c). 3060
(d). 1890
(e). None of these

6. A Committee is 5 in which 2 men teachers, 2 women teachers and 1 doctor are there
(a). 75
(b). 150
(c). 214
(d). 20
(e). None of these

8. A Committee of 3 in which there is no teacher and no doctor
(a). 100
(b). 120
(c). 10
(d). 12
(e). None of these

Probability Questions for IBPS RRB 2013 Answers

1. (d) Total number of marbles = 8 + 3 + 5 = 16
n(S) = Exhaustive number of cases
= Number of ways of drawing 4 marbles out of 16
n(E) = Number of cases when 2 marbles are red and 2 are blue.
∴ Required probability

2. (e)
n(S)
Required probability

3. (c)
n(S)
Out of the three drawn marbles none is red.
Clearly they will be either blue or green.

4. (a)The committee consists of 3 men and 2 women.
Out of 10 men. 3 men can be selected in 10C3 ways
and out of 8 woman can be selected in 8C2 ways
∴ Total number of selections = 10C3 × 8C2
= 3360

6. (b) Out of 5 men 2 teachers, can be selected in 5C2 ways.
Out of 3 women teachers, 2 can be selected in 3C2 ways.
Out of 5 doctors 1 can be selected in 5C1 ways.
∴ Total number of selections = 5C2 × 3C2 × 5C1
= 10 × 3 × 5 = 150

7. (a) Out of 18 persons, a committee of 7 persons is to be formed.
Total number of selections = 18C7

8. (c) The committee has no teachers and no doctor.
Out of 18 persons, there are 8 teacher and 5 doctors.
∴ Total number of selections =Number of ways of selecting 3 persons out of remaining 5 persons.